The invention relates to a transmission coupling assembly for absorbing axial and/or angular displacement between an internal combustion engine and a downstream gear train. The invention is particularly suited for use in utility vehicles or agricultural tractors having resiliently mounted engines.
In utility vehicles such as agricultural tractors, for example, which are built to a semi-chassis design, the drive motor, which is more often than not a diesel engine, may be resiliently mounted on a frame which is mounted by means of flanges on the gearbox housing. The drive motor and the gearbox housing are often spaced apart from one another to provide room for auxiliary drives (eg hydraulic pumps) which are mounted by means of flanges on the end face of the gearbox housing. Hydraulic pumps are required in say, a tractor, to supply hydraulic oil to the linkage lift mechanism and steering mechanism and for gear lubrication.
In order to compensate for relative axial and angular displacement between the engine output shaft and gear input shaft, the power is transmitted from the drive motor to the gearbox via an articulated shaft with longitudinal compensation, coupled with the engine output shaft and the gearbox input shaft by means of suitably sized flanges (see DE 38 34 919 A1). Because of the amount of space required for these flange mountings, the above-mentioned hydraulic pumps cannot be arranged as close to one another as their actual external dimensions would allow. Larger pump drive gears are needed in the gearbox in order to bridge the distance, which in turn means having to increase the width of the gearbox housing in an undesirable manner.
Hand in hand with the increased space requirement for the hydraulic pumps, the semi-chassis frame also needs to be made wider and this is undesirable since it places a restriction on the size of the steering lock angle of the steered front wheels.